FIELD OF THE INVENTION
The present invention relates to a shampoo composition. More particularly, the present invention relates to a shampoo composition which can impart good suppleness and good smoothness to hair and improve the adaptability of hair to combing and brushing.
In general, when hair is washed with a hair shampoo, the sebum supplied from sebaceous glands is washed away, the touch or feel of the hair is worsened and it is difficult to run a comb through the washed hair. Especially, in the case of long hair of women, hairdressing is very difficult after washing.
In order to obviate this disadvantage, a hair rinsing agent comprising as the main component a cationic surface active agent having a long-chain alkyl group has heretofore been used for the treatment of hair previously washed with a shampoo. Such cationic surface active agent having a long-chain alkyl group is adsorbed on hair and, as is well known in the art, it exerts the effects of softening the touch or feel of hair and facilitating combing thereof. In general, the main component of a hair shampoo is an anionic surface active agent, and therefore, it is impossible to incorporate into a shampoo composition a cationic surface active agent of the type that is used in hair rinsing agents because the anionic and cationic surface active agents react with each other, resulting in the formation of precipitates. As a means for preventing this undesirable phenomenon, there has been proposed a shampoo for imparting a good finish to hair, in which an amphoteric surface active agent is used instead of the anionic surface active agent and it is combined with a cationic surface active agent (see, for example, Japanese Patent Publication No. 17363/73). However, amphoteric surface active agents are more expensive than anionic surface active agents and they are disadvantageous because they are inferior with respect to their washing power and foaming property. Therefore, such a shampoo has not yet been commercially marketed. It has been reported that a very special cationic surface active agent can be incorporated in a shampoo comprising as the basic ingredient an anionic surface active agent (see, for example, Japanese Patent Publication No. 47845/72).
In order to improve the touch or feel of hair washed with a shampoo, it has been attempted to incorporate an oily substance, such as liquid paraffin, into a shampoo comprising an anionic surface active agent as the basic ingredient. In this case, however, in order to prevent reduction of the principal properties of the shampoo, such as the foaming property and washing power, the amount of such oily substance contained in the shampoo must be limited and a satisfactory effect cannot be obtained.